James Clerk Maxwell

Newton, Einstein, Maxwell. Three great scientists who all played crucial roles in our understanding of our physical world. Many modern physicists would in fact rank these three names as the greatest.

Maxwell was born on 13 June 1831 in Edinburgh. His father was a lawyer and added the second surname Maxwell after inheriting the Middlebie estate from Maxwell ancestors. Shortly after, the family moved from Edinburgh to Glenlair, the country house on the estate. Maxwell's parents had married late in life, and he was an only child. His mother died in 1839 from abdominal cancer. Maxwell was to die from the same disease, at the very same age.

An amiable, good natured and witty man, he seemingly breezed through science with no visible effort. His first scientific paper was at the age of 14, describing a series of oval curves which could be traced with pins and threads, much as ellipses can be drawn. He entered Edinburgh University at the age of 16, publishing two more papers. Cambridge University was next to feel the impact of his mind. His mathematics teacher, William Hopkins, is reported to have said that he was the most extraordinary man he had met with.

In 1856 he was appointed to the chair of natural philosophy at Marischal College, Aberdeen, having wished to move back to Scotland as his father was ill. But before he could take up the seat his father died. His personal life cheered up in 1858 when he married Katherine Dewar, the principal's daughter. Unfortunately, Scotland was fated not to hold onto him. In 1860 Marischal and King's Colleges merged to form the University of Aberdeen, and Maxwell was made redundant. He applied for a job at Edinburgh University, but was beaten to it by a school friend. He settled for the chair of natural philosophy at King's College, London.

In 1865 he retired, moving back to the family estate. He used most of this time to write his famous treatise on electricity and magnetism. In 1931, on the centenary of his birth, Einstein described the results of Maxwell's work as 'the most profound and the most fruitful that physics has experienced since the time of Newton.'

Before Maxwell, Michael Faraday had observed electric and magnetic lines of force. In the 1870s, Maxwell summarised these phenomena in four field equations. They are worth writing down here, even if they bring back memories of science labs.

2. There are no single, isolated magnetic poles (if there is a north, there will be an equivalent south pole).

3. Electrical currents can cause magnetic fields.

4. Changing magnetic fields can cause electrical currents.

Maxwell showed mathematically that an oscillating electric and magnetic field would propagate through space at the speed of light, demonstrating that light was, in fact, a form of electromagnetic radiation. He also predicted other types of radiation beyond visible light.

This work opened up the path leading towards Einstein's special theory of relativity (which established that mass and energy were the same). It also led towards Max Planck's formulation of the quantum hypothesis (that radiant-heat energy is emitted only in finite amounts, or quanta).

He made significant findings in the field of colours, gases, and theoretical physics. While still in his 20s, he wrote a prize-winning essay on Saturn's rings, concluding that they must be composed of separate masses. This was only corroborated more than a century later, when the first Voyager space probe flew past the giant planet. His work on geometrical optics led to the discovery of the fish-eye lens.

Maxwell is one of those characters, found in every field of human endeavour, who stands out. He died in Cambridge on Guy Fawkes' Night, 1879, as the skies no doubt pulsed and throbbed with colours, sounds and other forms of radiating waves. He received no public honours, and was buried quietly in a small churchyard in the Scottish village of Parton.